1. Field of the Invention (Technical Field)
The presently claimed invention generally relates to tire tools and more particularly to a hand operated portable tire demounting tool and assisting components thereof.
2. Background Art
There is a large variety of hand operated and power assisted tire demounting tools on the market. They range from simple pry bars too geometrically complex leveraging devices, along with power operated demounting devices.
With the wide range of composite materials, sizes, bead shapes, and method of manufacture for tire and wheel assemblies, there are a number of inherent limitations to the current methods and apparatus for tire demounting. These limitations range from functionality to adaptability. They fail to address some key factors in the successful removal of a tire from the rim or wheel assembly.
The functionally of the prior art systems for demounting tires is limited in a number of ways. Many conventional pry spoons and bars are made with a narrow design in relationship to the tire bead. This results in damage and tearing of the tire bead while trying to remove the tire from the wheel. The construction of low profile tires also is a limiting factor for many of the current tools. These low profile sidewalls and the use of multi-ply steel or fiber construction, make these tires stiff and difficult to work with. Power operated devices tend to tear and ruin the bead of these types of tires. Hand tools often prove ineffective, having neither the shape to conform to such tires or the prying force to extract it from the rim or wheel. Removal of these tires with the current devices results in damaging the tire beyond repair, and, thus, defeating the purpose of repairing and remounting the tire.
A further limiting factor for many of the current tools is removal of soft side wall tires with a highly pliable bead. These tires present the problem of having a bead that stretches, but becomes difficult to extract from the wheel. The highly pliable bead will typically be pried above the rim only in the area directly engaged by the tool or pry bar. Disengaging the tool from this area will cause the elastic bead to return to its original position, thus failing to remove the tire from the rim. The narrow hand operated spoons and pry bars are especially susceptible to this malfunction and there is often the added consequence of bead tearing.
The current conventional hand tire demounting tools fail in their adaptability because they are confined to being used with specific sized tires and wheel assemblies. Power type tools are also limited in their range of size, type of wheel, and tire assemblies to work effectively. The power operated tools are further limited in their ability to work in remote locations away from air, electric, hydraulic or other power sources. Further, some wheel assemblies have “a reverse wheel” having the main part of the hub center offset to the top of the demounting side. This type of hub center limits the leveraging stroke of the current pry bar type tools to such a degree that they are ineffective.
Finally, these prior art methods, whether power or hand operated tire demounting systems, fail to address a key issue in the successful demounting of a tire from its rim assembly, namely the manipulation of the bead into a shallow channel that is referred to as the drop center of the wheel assembly during the demounting procedure. This drop center is a channel in the wheel assembly running parallel to the plain of the rim flanges, and having a circumference smaller than the rim flanges in the trough of the channel. The tire bead must be directed into this channel or trough on the opposite side from which the demount tool engages the bead during the demounting procedure. Channeling the bead into this drop center in this fashion allows enough slack in the tire bead so it may be removed from the rim without excessive stretching or tearing of the bead. The prior art methods, whether power or hand operated tire demounting systems, have no mechanical means to ensure that the bead is in the drop center, thereby allowing undue pressure to be placed on the tire bead during demounting and causing further damage to the bead or resulting in an unsuccessful demounting procedure.